Case for Screening Magnetic Fields

Abstract

The present invention concerns a case for screening magnetic fields, comprising at least two parts, and more particularly a lower part ( 4, 5 ) and a bell-shaped upper part ( 3 ). These parts are of a shape such that they are able to envelop a movement ( 1 ) of a timepiece. The upper part ( 3 ), moreover, is attached in such a way that while attached to the movement, it is able to move in a plane parallel to the movement ( 1 ) while it is essentially immobile in a direction normal to this plane.

1 . Case for a screening of magnetic fields, comprising at least two parts, a lower part ( 4 ,  5 ) and a bell-shaped upper part ( 3 ), adapted to envelop a movement ( 1 ) of a timepiece, characterized in that the bell-shaped upper part ( 3 ) is attached in such a way that it may move within a plane parallel to the movement ( 1 ) while it is essentially immobile in a direction normal to this plane. 
     
     
         2 . Case according to  claim 1 , characterized in that the mobility of the attachment of the bell-shaped upper part ( 3 ) in the plane parallel to the movement is accomplished with screws ( 9 ) and washers ( 10 ). 
     
     
         3 . Case according to  claim 2 , characterized in that each washer ( 10 ) in its longitudinal direction has two segments ( 10 . 1 ,  10 . 2 ) differing in their diameters, the bottom side ( 10 . 3 ) of the upper, larger segment ( 10 . 1 ) of washer ( 10 ) being adapted to hold the bell-shaped upper part ( 3 ) against the movement ( 1 ). 
     
     
         4 . Case according to  claim 2 , characterized in that the upper surface ( 10 . 4 ) of washers ( 10 ) provides that dial ( 6 ) that is mounted above the bell-shaped upper part ( 3 ) will be in a spaced-apart position from the surface of the bell-shaped upper part ( 3 ). 
     
     
         5 . Case according to  claim 4 , characterized in that around the display arbors of the movement ( 1 ) that penetrate the bell-shaped upper part ( 3 ), anchoring pipes ( 11 ) are mounted, their upper surface turned toward the dial ( 6 ) being slightly below the upper surfaces ( 10 . 4 ) of the washers ( 10 ) so that support of the dial ( 6 ) that is attached above the bell-shaped upper part ( 3 ), and its spaced-apart position from the surface of the upper bell-shaped part ( 3 ) are secured. 
     
     
         6 . Case according to  claim 3 , characterized in that the bell-shaped upper part ( 3 ) has cylindrical passages ( 3 . 1 ) for the screws ( 9 ) and washers ( 10 ), each of said passages ( 3 . 1 ) including two segments ( 3 . 1 . 1 ,  3 . 1 . 2 ) differing in their diameters and slightly larger in their dimensions than the corresponding segment ( 10 . 1 ,  10 . 2 ) of the washer ( 10 ) to be positioned in them. 
     
     
         7 . Case according to  claim 3 , characterized in that opposite to the cylindrical passages ( 3 . 1 ) of the bell-shaped upper part ( 3 ), movement ( 1 ) has recesses ( 1 . 1 ) with diameters slightly larger than the diameter of the lower segment ( 10 . 2 ) of washer ( 10 ), and with a height that, taken together with the thickness of the lower segment ( 3 . 1 . 2 ) of the cylindrical passage ( 3 . 1 ), matches the height of the lower segment ( 10 . 2 ) of washer ( 10 ). 
     
     
         8 . Case according to  claim 1 , characterized in that the inner wall of the bell-shaped upper part ( 3 ) has an annular groove ( 3 . 4 ) into which an elastic element ( 12 ,  13 ,  14 ) sitting on the outer wall of movement ( 1 ) may engage so as to position the bell-shaped upper part ( 3 ) on movement ( 1 ). 
     
     
         9 . Case according to  claim 8 , characterized in that the elastic element is formed as an open annular spring ( 12 ) sitting in an annular groove ( 1 . 2 ) on the outside of movement ( 1 ). 
     
     
         10 . Case according to  claim 9 , characterized in that the elastic element is formed as a gasket ( 13 ) sitting in an annular groove ( 1 . 2 ) on the outside of movement ( 1 ). 
     
     
         11 . Case according to  claim 10 , characterized in that the elastic element is formed as an elastic button ( 14 ). 
     
     
         12 . Case according to  claim 1 , characterized in that the bell-shaped upper part ( 3 ) has through holes ( 3 . 3 ) admitting feet of a dial ( 6 ) serving to fasten the dial ( 6 ) to the movement ( 1 ). 
     
     
         13 . Case according to  claim 1 , characterized in that the lower part consists of two separate parts, a bottom ( 5 ) and an annular middle part ( 4 ), that can be joined together. 
     
     
         14 . Case according to  claim 1 , characterized in that the lower part ( 4 ,  5 ) and the bell-shaped upper part ( 3 ) consist of magnetically nonconductive material. 
     
     
         15 . Case according to  claim 14 , characterized in that the lower part ( 4 ,  5 ) and the bell-shaped upper part ( 3 ) consist of soft iron. 
     
     
         16 . Timepiece, and more particularly wristwatch, characterized in that it comprises a case according to  claim 1 . 
     
     
         17 . Case according to  claim 4 , characterized in that the bell-shaped upper part ( 3 ) has cylindrical passages ( 3 . 1 ) for the screws ( 9 ) and washers ( 10 ), each of said passages ( 3 . 1 ) including two segments ( 3 . 1 . 1 ,  3 . 1 . 2 ) differing in their diameters and slightly larger in their dimensions than the corresponding segment ( 10 . 1 ,  10 . 2 ) of the washer ( 10 ) to be positioned in them. 
     
     
         18 . Case according to  claim 5 , characterized in that the bell-shaped upper part ( 3 ) has cylindrical passages ( 3 . 1 ) for the screws ( 9 ) and washers ( 10 ), each of said passages ( 3 . 1 ) including two segments ( 3 . 1 . 1 ,  3 . 1 . 2 ) differing in their diameters and slightly larger in their dimensions than the corresponding segment ( 10 . 1 ,  10 . 2 ) of the washer ( 10 ) to be positioned in them. 
     
     
         19 . Case according to  claim 3 , characterized in that the upper surface ( 10 . 4 ) of washers ( 10 ) provides that dial ( 6 ) that is mounted above the bell-shaped upper part ( 3 ) will be in a spaced-apart position from the surface of the bell-shaped upper part ( 3 ). 
     
     
         20 . Case according to  claim 4 , characterized in that opposite to the cylindrical passages ( 3 . 1 ) of the bell-shaped upper part ( 3 ), movement ( 1 ) has recesses ( 1 . 1 ) with diameters slightly larger than the diameter of the lower segment ( 10 . 2 ) of washer ( 10 ), and with a height that, taken together with the thickness of the lower segment ( 3 . 1 . 2 ) of the cylindrical passage ( 3 . 1 ), matches the height of the lower segment ( 10 . 2 ) of washer ( 10 ).